JPS5889944A - Chemical vapor depositing device with plasma - Google Patents

Abstract

PURPOSE:To remove dust efficiently by providing an ejection port and a suction port for high pressure gas in a reacting furnace and operating these simultaneously. CONSTITUTION:The inside of a vacuum vessel 4 is evacuated to vacuum through an evacuating port 12 when a valve 11 is opened. Plasma discharge is generated by high voltage of high frequency or DC between a base cylinder 8 and electrodes 7. The electrodes 7 decompose raw material gas by plasma and deposit the same as film on the base body 8. A high pressure gas is ejected through a piping 2 and through nozzles 16 into the furnace to remove the unnecessary films stuck on the shielding plate and the electrodes. At the same time, a valve 13 is opened to suck and collect the dust with a vacuum cleaner 15 installed to a piping 14.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a plasma CVD apparatus provided with a mechanism for efficiently collecting dust particles generated within the plasma CVD apparatus.

One of the thin film manufacturing methods that has been in the spotlight in recent years is the Gradama CVD method. In this method, the pressure in the reaction chamber is reduced to a high vacuum, the raw material gas is supplied to the reaction chamber, the raw material gas is decomposed by direct current or high frequency glow discharge, and a thin film is formed on a substrate placed inside the reaction chamber. For example, it is applied to the production of amorphous silicon films.

An amorphous silicon film created by this method using, for example, silane gas (81H4) as a raw material gas has relatively few localized levels in the forbidden band of amorphous silicon, has high resistance, and has high light guiding properties. , is effective as a photoreceptor for electrophotography.

When a photoreceptor for electrophotography is manufactured by this method, it is necessary to increase the acceptance potential of the amorphous photosensitive layer, and the thickness of the amorphous film is required to be about 15 to 20 μm.

On the other hand, in a normal plasma CVD apparatus, the film is formed on all surfaces exposed to the plasma, such as the counter electrode other than the target cylindrical substrate, the electric shield plate for containing the plasma, and the raw material gas introduction tube. After manufacturing a thick film several times, the film adhering to the outer wall becomes particles or powder that fly up due to the flow of air in the vacuum tank when outside air is introduced into the vacuum tank or when the vacuum is evacuated, and the film adheres to the outer wall. It sticks to the cylinder as dust.

These dusts deteriorate the quality of the photoreceptor and reduce the retention of non-defective products.

In order to remove such dust, it has conventionally been necessary to take out the reactor from the vacuum chamber, disassemble it, and clean it every time a film is formed.

The present invention provides a Glazma C'VD equipped with a mechanism for efficiently removing these generated slags without dismantling the reactor.
It is a device.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in detail below with reference to embodiments shown in the drawings.

In the figure, 4 is a vacuum chamber housing a reactor.

By opening the pulp 11, this vacuum chamber is evacuated through the evacuation taro 12 connected to the vacuum pumper.

High wave or DC high voltage, base cylinder 8 and electrode 70
A plasma discharge is generated in between. The electrode 7 also plays the role of introducing the source gas, plasma decomposing the source gas and depositing it on the substrate 8 as a film.

In this case, it is best to rotate the cylindrical base by the rotating shaft 3 and heat the inside of the cylindrical base by the heater 9.

Furthermore, in order to electrically confine the plasma, a shield plate such as the one shown at 5.6° lO is used.

It is ejected from the nozzle 16 into the inside of the furnace to remove unnecessary films attached to the shield plate and electrodes, and at the same time the Pal f13
Open it and use the vacuum cleaner 15 attached to the pipe 14 to
Collect dust by suction. Since this operation is performed before attaching the cylindrical base, there is no need to worry about dust getting on the cylinder. The valves 1 and 13 are then closed, the base cylinder is rubbed against the rotating shaft, the vacuum chamber is sealed, the pallet 211 is opened, and the vacuum pump 12 evacuates the chamber.

By performing the above operations at the end of each film forming process, the cylindrical substrate is always kept clean.

Generally, when forming a semiconductor film as in this example, contaminating the reactor part of the equipment with active impurities will significantly impair the electrical properties of the film formed by the reactor. Therefore, it is desirable to use an inert gas such as nitrogen or alponic as the high-pressure gas, but it is also possible to use clean air.

Regarding the nozzle ejection direction, number, and mounting location, it is more effective to direct the nozzle toward a place where a lot of powder tends to adhere. It is necessary to take this into consideration when making a decision.

In this embodiment, a dust collector 15 is provided, but any method may be used as long as the removed dust does not affect others. Further, the structure of the nozzle itself may be a shower type nozzle with many holes.

By configuring the plasma CVD apparatus of the present invention as described above, it exhibits an excellent function that greatly simplifies the cleaning work that conventionally required manual labor, and at the same time makes it possible to automate each process. .

[Brief explanation of the drawing]

The drawing shows a plasma CVD device equipped with a cleaning mechanism according to the present invention.
FIG. 2 is a diagram showing an example device of the device. 1...Pulp 2...High pressure piping 3...
・Rotating shaft 4...Vacuum chamber 5 e 6 e
10... Plasma shield 7... Electrode/raw material gas ejector

Claims (1)

[Claims] A plasma CVD apparatus characterized in that a high-pressure gas jet port and a suction port are provided in a reactor and are operated simultaneously to remove dust powder from the reactor.